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近来,不溶性高聚物品种不断增加,要求测定分子量和分子量分布的呼声日益高涨。本文介绍用熔融指数、挤出胀大、密度和结晶热等指标作为相对量度的方法。端基由于每一个大分子有一个或两个端基,测出端基含量便可推算其数均分子量n。如:用过硫酸盐引发的水相聚合的高聚物有末端羧基,可用红外光谱测定。用NaH~(35)SO_3引发时,端基中有标记~(35)S可供测定。岐化终止的大分子链一端带有羧基,而再
Recently, the number of insoluble polymer species has been increasing, and calls for determination of molecular weight and molecular weight distribution have been increasing. This article describes the use of melt index, extrusion swell, density and heat of crystallization and other indicators as a relative measure. End groups As each macromolecule has one or two end groups, the end group content can be measured to calculate its number average molecular weight n. Such as: the use of persulfate-induced polymerization of water-based polymers have carboxyl terminal, infrared spectroscopy. With the initiation of NaH ~ (35) SO_3, the terminal group with ~ (35) S can be measured. Disulfide termination of the macromolecular chain with carboxyl groups at one end, and then